1. Field of the Invention
This invention relates to a clutch mechanism and more particularly to an improved, compact, effective clutch assembly effective to engage and disengage a power source and a load.
2. Description of the Prior Art
As is known, clutches generally fall into two classes, the positive or jaw clutch and the friction clutch. In the jaw clutch it is usually necessary to move either the driven or driving member axially to disengage the clutch teeth. Normally a shifting device is used which engages a groove on one of the shafts. The jaw clutch, though simple in construction, is normally used where it is not objectionable to start the driven member or load suddenly. The objection to this type of clutch is the need for relative axial movement and for some device to shift the clutch components.
In the friction clutch, there is usually slip during engagement while the driven member is accelerated, and again, there is usually some relative axial movement between the driving and driven parts and a shifting device is usually needed.
There are situations, however, in which it is desirable to eliminate the relative axial movement normally used in friction and jaw clutches to effect engagement and disengagement of the clutch. Moreover, the use of a shifting device is sometimes objectionable because of the complexity which this adds to a clutch mechanism.
There are instances in which it is desirable to disengage driving and driven members quickly and almost instantaneously in the event of stoppage of load movement or of power source and to effect engagement once the stoppage ceases. Conventional friction clutches normally do not function instantaneously and usually require some component of the clutch to move axially. Again, in the case of a conventional jaw clutch, there is usually the need for axial relative movement.
For example, in a device driven by motor and in which a load is continuously moving in normal operation, some stoppage in the load train may require quick decoupling of the motor drive components from the load components in order to stop movement of the load components for functional or safety reasons. While stoppage may be accomplished by using a brake on the motor, this complicates motor design and motor control component design. While a jaw type clutch may be used, the need for relative axial movement and for a clutch control device renders the clutch design somewhat complex.
A typical instance in which almost instantaneous disengagement of the drive and driven components is needed is in the case of an externally powered gun. In this type of movement, gun function is controlled through an external power source, usually an electric motor. If for some reason there is a malfunction, it is desirable to stop gun function quickly, and perhaps with gun components (bolt and feed mechanism) in a prescribed position for safety reasons. It may also be desirable to control gun shut-down so that in a normal stop fire sequence, gun components are located in a precise position e.g. an open bolt normal gun shut-down mode.
Thus, it is an object of this invention to provide an improved clutch mechanism in which engagement and disengagement of the clutch is automatic without the need for any shifting mechanism.
It is also an object of this invention to provide an effective automatic operating clutch mechanism of compact design and wherein there is no relative axial movement of the clutch components.
Still another object of the present invention is the provision of a relatively simple clutch assembly which operates automatically and almost instantaneously absent any shifting mechanism and without the need for relative axial movement of the clutch assembly component parts.